Berry Big Chickens

Researcher Shows How to Plump Up Poultry Without Risk of Antibiotic Resistance

by Chris Carroll | Illustration by Jason Keisling

Taking the healthy route by opting for the grilled chicken might come with an unexpected side order—a dose of the antibiotics some farmers use to grow bigger, meatier fryers.

Widespread overuse of these one-time wonder drugs is decreasing their effectiveness against pathogens that infect people, so researchers in the College of Agriculture and Natural Resources have demonstrated a new way of bulking up poultry. And it eliminates the danger of antibiotic resistance because the key ingredient isn’t a drug.

“Berries are really good for us, with an anti-inflammatory effect,” says Debabrata Biswas, the assistant professor of animal and avian sciences leading the study. “They seem to be good for chickens as well.”

Adding a small dose of the extract made from blueberry and blackberry pomace—leftovers after the berries are mashed for juice—to water resulted in chicks about six percent plumper than those that drank plain water, according to a study published in October in Frontiers in Microbiology. That’s likely the berries’ anti-inflammatory effect in action, Biswas says. In higher doses, he says, it seems to prevent illnesses similarly to antibiotics.

It doesn’t stimulate growth quite as dramatically as antibiotic growth promoters (AGPs)—cocktails of erythromycin, bacitracin and other human-use drugs that caused an average 9.5 percent weight gain—but it also doesn’t carry the risks that are driving chicken producers to bow to consumer demand and phase out AGPs. Maryland-based Perdue Farms stopped using them a decade ago, and the nation’s No. 1 producer, Tyson Foods, said it stopped using antibiotics this past summer. But there’s no reason to fear a future of scrawny drumsticks, thanks to Biswas’ berry concoction.